Conditions for Setting the DTC: P0601
WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The ECM checksum value is incorrect for at least one sample. Each sample is 50 milliseconds. The ECM detects that the check sum value is incorrect for 0.05 second. This diagnostic runs continuous.